and thus of the shaft 23 by the screwing engagement between the stem 60 and the tapped bore 43 for this reason the stem 60 has a tooling end 66 i e flat engagement surfaces by which an appropriate tool may be used to rotate the wedge unit 26 it is pointed that other types of joints may be formed between the wedge unit 26 and the plug unit 24 according to an embodiment any appropriate one degree of freedom translational joint may be used such as a sliding joint a cylindrical joint etc as alternatives to the screw joint the plug device 20 in the contracted configuration of fig5 is sized to be inserted in the bore 32 of the shaft 23 with the legs 50 being in a contracted position the bore 32 of the shaft 23 defines a throat by the presence of the splines 33 or like projections however the diameter of the plug device 20 is small enough for the feet 51 to move axially beyond the splines 33 in the shaft 23 once the feet 51 are beyond the splines 33 the wedge unit 26 is moved axially relative to the annular plug unit 24 in the illustrated embodiment the wedge unit 26 is screwingly rotated the annular plug unit 24 does not rotate because of the alignment pins 47 being engaged with the splines 33 as the wedge unit 26 moves axially along the shaft 23 the wedge portion 65 will contact the end of the legs 50 thereby pushing the feet 51 radially outwardly to a deployed position of the legs the feet 51 therefore.