Safety release device useful in tapping attachments

As an article of manufacture, an apparatus for providing a releasable joint between telescoping cylindrical members comprising an inner member and an outer member, radially movable means carried by the outer member, and the inner member having means constructed to be engageable by said radially movable means in a manner to prevent relative axial movement of the inner and outer members, and relatively movable actuator means carried by the outer member and having means positionable in a manner to allow the said radially movable means to move outward radially to disengage from the said inner member whereby to allow for relative axial movement as between the inner and outer members, wherein said actuator means is deformable sufficiently whereby in response to predetermined torque load, said radially movable member can be moved radially sufficiently to disengage from the inner member, wherein the said actuator means is in the form of a split ring, wherein said inner member has a recess having the shape of a part of a sphere, said radially movable means being a ball, said inner member having a helical groove in it, said recess being at one end of the said groove whereby upon stoppage of rotation of the inner member while the outer member continues to rotate, said radially movable ball can follow said helical groove, causing the outer member to move axially relative to the inner member.